The uncle of a 12-year-old boy who had a pellet gun when he was shot by a Cleveland police officer told mourners at a memorial service Wednesday that they must be advocates for change through peaceful protest and civil disobedience.

Tamir Rice's uncle also said that police need to revamp how they train officers while also looking closer at police brutality and the use of excessive force.

Surveillance video released by police shows Tamir being shot within 2 seconds of a patrol car stopping near him at a park on Nov. 22. It shows the boy reaching in his waistband for what police discovered was an airsoft gun, which shoots non-lethal plastic projectiles. He died the next day.

Police said rookie officer Tim Loehmann believed the boy had a real firearm.

Loehmann joined Cleveland police in March after spending six months in 2012 with the police department in suburban Independence.

Personnel files released Wednesday showed police supervisors in Independence decided he lacked the maturity needed to work in their department. A letter in his file said there was a pattern of a lack of discretion and of not following instructions.

"In law enforcement there are times when instructions need be followed to the letter, and I am under the impression Ptl. Loehmann, under certain circumstances, will not react in the way instructed," the letter said.

Loehmann resigned from the Independence police department in December 2012 after meeting his supervisors about their concerns.

Cleveland police said in a statement Wednesday night that the agency did not review Loehmann's department personnel file from Independence before hiring him. However, detectives talked to the human resources director in that suburb and were told there were no issues that would make him an undesirable candidate. The detectives were told Loehmann had resigned from the Independence department for personal reasons.

A grand jury will consider whether charges are merited.

Just days after the shooting, protesters marched past City Hall and temporarily blocked rush-hour traffic on a busy Cleveland freeway.

Several hundred people attended the memorial service for Tamir at Mount Sinai Baptist Church.

Family members and friends, some wearing shirts with Tamir's picture, filed past displays of photos at the front of the church and stopped to hug his mother.

One of his former teachers said Tamir liked to draw, play basketball and the drums.

The uncle of a 12-year-old boy who had a pellet gun when he was shot by a Cleveland police officer told mourners at a memorial service Wednesday that they must be advocates for change through peaceful protest and civil disobedience.Tamir Rice's uncle also said that police...